Naturalisation (biology)

Naturalisation (or naturalization) is the

Generally, any introduced species may (in the wild) either go extinct or naturalise in its new environment ^[3].

Some populations do not sustain themselves reproductively, but exist because of continued influx from elsewhere. Such a non-sustaining population, or the individuals within it, are said to be

Two categories of naturalisation are defined from two distinct parameters: one, archaeonaturalised, refers to introduction before a given time (introduced over a hundred years ago), while the second, amphinaturalised or eurynaturalised, implies a notion of spatial extension (taxon assimilated indigenous and present over a vast space, opposed to stenonaturalised).^[clarification needed]^{[citation needed]}

Degrees of naturalisation

The degrees of naturalisation are defined in relation to the status of

• Accidental taxon: non-
  native
  taxon growing spontaneously, which appears sporadically as a result of accidental introduction due to human activities (as opposed to intentional introductions)
• Subspontaneous taxon: taxon naturalised following an introduction of accidental origin (fortuitous introduction linked to human activities) or unknown, and which, after acclimatization, can reproduce like native plants but is still poorly established
• Spontaneous taxon: native or non-native taxon growing and reproducing naturally, without intentional human intervention in the territory considered, and is well established (mixes with local flora or fauna)

Zoology

Animal naturalisation is mainly carried out through breeding and by commensalism following human migrations.^[5][6]

The concerned species are thus:

• either introduced voluntarily into an ecosystem where they are not native;
• either accidentally introduced or become feral;
• or by naturally following human migratory flows by commensalism (eg: arrival of house sparrow in Western Europe following Huns, and previously in Eastern Europe from Asia Minor in Antiquity).

It sometimes happens that a naturalised species hybridizes with a native.^[6]

Introduction and origin areas

The introduction site or introduction area is the place or, in a broadlier way, the new environment where the candidate species for naturalisation takes root. It is generally opposed to the origin area, where this same species is native.

There is also a more ambiguous notion that is the "natural distribution area" or "natural distribution range", particularly when it comes to

Naturalisation is sometimes done with human help in order to replace another species having suffered directly or indirectly from anthropogenic activities, or deemed less profitable for human use.[7]

Some naturalised species eventually become

Some naturalised species, such as palms, can act as ecosystem engineers, by changing the habitat and creating new niches that can sometimes have positive effects on an ecosystem. Potential and/or perceived positive impacts of naturalised species are less studied than potential and/or perceived negative impacts.^[10]

However, the impact on local species is not easy to assess in a short period. For instance, the

Naturalised species may become invasive species if they become sufficiently abundant to have an adverse effect on native species (e.g. microbes affected by invasive plants^[12]) or on biotope.^[13]

See also

• Adventitious plant
• Adventive species
• Colonisation (biology)
• Cosmopolitan distribution
• Endemism
• Hemerochory
• Indigenous (ecology)

References